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git.proxmox.com Git - mirror_frr.git/blob - lib/compiler.h
2 * Copyright (c) 2015-2017 David Lamparter, for NetDEF, Inc.
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 #ifndef _FRR_COMPILER_H
18 #define _FRR_COMPILER_H
25 # if __cplusplus < 201103L
26 # error FRRouting headers must be compiled in C++11 mode or newer
28 /* C++ defines static_assert(), but not _Static_assert(). C defines
29 * _Static_assert() and has static_assert() in <assert.h>. However, we mess
30 * with assert() in zassert.h so let's not include <assert.h> here.
32 # define _Static_assert static_assert
34 # if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
35 # error FRRouting must be compiled with min. -std=gnu11 (GNU ISO C11 dialect)
39 /* function attributes, use like
40 * void prototype(void) __attribute__((_CONSTRUCTOR(100)));
42 #if defined(__clang__)
43 #if __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 5)
44 # define _RET_NONNULL , returns_nonnull
46 #if __has_attribute(fallthrough)
47 # define _FALLTHROUGH __attribute__((fallthrough));
49 # define _CONSTRUCTOR(x) constructor(x)
50 # define _DEPRECATED(x) deprecated(x)
51 # if __has_builtin(assume)
52 # define assume(x) __builtin_assume(x)
54 #elif defined(__GNUC__)
55 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
56 # define _RET_NONNULL , returns_nonnull
58 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
59 # define _CONSTRUCTOR(x) constructor(x)
60 # define _DESTRUCTOR(x) destructor(x)
61 # define _ALLOC_SIZE(x) alloc_size(x)
63 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
64 # define _DEPRECATED(x) deprecated(x)
65 # define assume(x) do { if (!(x)) __builtin_unreachable(); } while (0)
68 # define __has_attribute(x) 0
71 # define _FALLTHROUGH __attribute__((fallthrough));
75 #if __has_attribute(hot)
76 # define _OPTIMIZE_HOT __attribute__((hot))
78 # define _OPTIMIZE_HOT
80 #if __has_attribute(optimize)
81 # define _OPTIMIZE_O3 __attribute__((optimize("3")))
85 #define OPTIMIZE _OPTIMIZE_O3 _OPTIMIZE_HOT
87 #if !defined(__GNUC__)
88 #error module code needs GCC visibility extensions
90 #error module code needs GCC visibility extensions
92 # define DSO_PUBLIC __attribute__ ((visibility ("default")))
93 # define DSO_SELF __attribute__ ((visibility ("protected")))
94 # define DSO_LOCAL __attribute__ ((visibility ("hidden")))
98 /* Solaris doesn't do constructor priorities due to linker restrictions */
103 /* fallback versions */
105 # define _RET_NONNULL
108 # define _CONSTRUCTOR(x) constructor
111 # define _DESTRUCTOR(x) destructor
114 # define _ALLOC_SIZE(x)
120 #define _DEPRECATED(x) deprecated
126 /* for helper functions defined inside macros */
127 #define macro_inline static inline __attribute__((unused))
128 #define macro_pure static inline __attribute__((unused, pure))
130 /* if the macro ends with a function definition */
131 #define MACRO_REQUIRE_SEMICOLON() \
132 _Static_assert(1, "please add a semicolon after this macro")
134 /* variadic macros, use like:
137 * #define V(...) MACRO_VARIANT(V, ##__VA_ARGS__)(__VA_ARGS__)
139 #define _MACRO_VARIANT(A0,A1,A2,A3,A4,A5,A6,A7,A8,A9,A10, N, ...) N
141 #define _CONCAT2(a, b) a ## b
142 #define _CONCAT(a, b) _CONCAT2(a,b)
144 #define MACRO_VARIANT(NAME, ...) \
145 _CONCAT(NAME, _MACRO_VARIANT(0, ##__VA_ARGS__, \
146 _10, _9, _8, _7, _6, _5, _4, _3, _2, _1, _0))
148 #define NAMECTR(name) _CONCAT(name, __COUNTER__)
150 /* per-arg repeat macros, use like:
151 * #define PERARG(n) ...n...
152 * #define FOO(...) MACRO_REPEAT(PERARG, ##__VA_ARGS__)
155 #define _MACRO_REPEAT_0(NAME)
156 #define _MACRO_REPEAT_1(NAME, A1) \
158 #define _MACRO_REPEAT_2(NAME, A1, A2) \
160 #define _MACRO_REPEAT_3(NAME, A1, A2, A3) \
161 NAME(A1) NAME(A2) NAME(A3)
162 #define _MACRO_REPEAT_4(NAME, A1, A2, A3, A4) \
163 NAME(A1) NAME(A2) NAME(A3) NAME(A4)
164 #define _MACRO_REPEAT_5(NAME, A1, A2, A3, A4, A5) \
165 NAME(A1) NAME(A2) NAME(A3) NAME(A4) NAME(A5)
166 #define _MACRO_REPEAT_6(NAME, A1, A2, A3, A4, A5, A6) \
167 NAME(A1) NAME(A2) NAME(A3) NAME(A4) NAME(A5) NAME(A6)
168 #define _MACRO_REPEAT_7(NAME, A1, A2, A3, A4, A5, A6, A7) \
169 NAME(A1) NAME(A2) NAME(A3) NAME(A4) NAME(A5) NAME(A6) NAME(A7)
170 #define _MACRO_REPEAT_8(NAME, A1, A2, A3, A4, A5, A6, A7, A8) \
171 NAME(A1) NAME(A2) NAME(A3) NAME(A4) NAME(A5) NAME(A6) NAME(A7) NAME(A8)
173 #define MACRO_REPEAT(NAME, ...) \
174 MACRO_VARIANT(_MACRO_REPEAT, ##__VA_ARGS__)(NAME, ##__VA_ARGS__)
177 * for warnings on macros, put in the macro content like this:
178 * #define MACRO BLA CPP_WARN("MACRO has been deprecated")
180 #define CPP_STR(X) #X
183 #define CPP_NOTICE(text) _Pragma(CPP_STR(message __FILE__ ": " text))
184 #define CPP_WARN(text) CPP_NOTICE(text)
186 #elif (defined(__GNUC__) \
187 && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))) \
188 || (defined(__clang__) \
189 && (__clang_major__ >= 4 \
190 || (__clang_major__ == 3 && __clang_minor__ >= 5)))
191 #define CPP_WARN(text) _Pragma(CPP_STR(GCC warning text))
192 #define CPP_NOTICE(text) _Pragma(CPP_STR(message text))
195 #define CPP_WARN(text)
196 #define CPP_NOTICE(text)
199 /* MAX / MIN are not commonly defined, but useful */
200 /* note: glibc sys/param.h has #define MIN(a,b) (((a)<(b))?(a):(b)) */
206 typeof(a) _max_a = (a); \
207 typeof(b) _max_b = (b); \
208 _max_a > _max_b ? _max_a : _max_b; \
215 typeof(a) _min_a = (a); \
216 typeof(b) _min_b = (b); \
217 _min_a < _min_b ? _min_a : _min_b; \
220 #define numcmp(a, b) \
222 typeof(a) _cmp_a = (a); \
223 typeof(b) _cmp_b = (b); \
224 (_cmp_a < _cmp_b) ? -1 : ((_cmp_a > _cmp_b) ? 1 : 0); \
228 #ifdef __compiler_offsetof
229 #define offsetof(TYPE, MEMBER) __compiler_offsetof(TYPE,MEMBER)
231 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
239 #if !(defined(__cplusplus) || defined(test__cplusplus))
240 /* this variant of container_of() retains 'const' on pointers without needing
241 * to be told to do so. The following will all work without warning:
244 * const struct member *cp;
246 * const struct cont *x = container_of(cp, struct cont, member);
247 * const struct cont *x = container_of(cp, const struct cont, member);
248 * const struct cont *x = container_of(p, struct cont, member);
249 * const struct cont *x = container_of(p, const struct cont, member);
250 * struct cont *x = container_of(p, struct cont, member);
252 * but the following will generate warnings about stripping const:
254 * struct cont *x = container_of(cp, struct cont, member);
255 * struct cont *x = container_of(cp, const struct cont, member);
256 * struct cont *x = container_of(p, const struct cont, member);
258 #define container_of(ptr, type, member) \
259 (__builtin_choose_expr( \
260 __builtin_types_compatible_p(typeof(&((type *)0)->member), \
262 || __builtin_types_compatible_p(void *, typeof(ptr)), \
264 typeof(((type *)0)->member) *__mptr = (void *)(ptr); \
265 (type *)((char *)__mptr - offsetof(type, member)); \
268 typeof(((const type *)0)->member) *__mptr = (ptr); \
269 (const type *)((const char *)__mptr - \
270 offsetof(type, member)); \
274 /* current C++ compilers don't have the builtins used above; so this version
275 * of the macro doesn't do the const check. */
276 #define container_of(ptr, type, member) \
278 const typeof(((type *)0)->member) *__mptr = (ptr); \
279 (type *)((char *)__mptr - offsetof(type, member)); \
283 #define container_of_null(ptr, type, member) \
285 typeof(ptr) _tmp = (ptr); \
286 _tmp ? container_of(_tmp, type, member) : NULL; \
289 #define array_size(ar) (sizeof(ar) / sizeof(ar[0]))
291 /* Some insane macros to count number of varargs to a functionlike macro */
293 _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, \
294 _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, \
295 _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, \
296 _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, \
297 _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, \
298 _51, _52, _53, _54, _55, _56, _57, _58, _59, _60, \
299 _61, _62, _63, N, ...) N
301 #define PP_RSEQ_N() \
303 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, \
304 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, \
305 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, \
306 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, \
307 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, \
308 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
310 #define PP_NARG_(...) PP_ARG_N(__VA_ARGS__)
311 #define PP_NARG(...) PP_NARG_(_, ##__VA_ARGS__, PP_RSEQ_N())
314 /* sigh. this is so ugly, it overflows and wraps to being nice again.
316 * printfrr() supports "%Ld" for <int64_t>, whatever that is typedef'd to.
317 * However, gcc & clang think that "%Ld" is <long long>, which doesn't quite
318 * match up since int64_t is <long> on a lot of 64-bit systems.
320 * If we have _FRR_ATTRIBUTE_PRINTFRR, we loaded a compiler plugin that
321 * replaces the whole format checking bits with a custom version that
322 * understands "%Ld" (along with "%pI4" and co.), so we don't need to do
325 * If we don't have that attribute... we still want -Wformat to work. So,
326 * this is the "f*ck it" approach and we just redefine int64_t to always be
327 * <long long>. This should work until such a time that <long long> is
328 * something else (e.g. 128-bit integer)... let's just guard against that
329 * with the _Static_assert below and work with the world we have right now,
330 * where <long long> is always 64-bit.
333 /* these need to be included before any of the following, so we can
334 * "overwrite" things.
337 #include <inttypes.h>
339 #ifdef _FRR_ATTRIBUTE_PRINTFRR
340 #define PRINTFRR(a, b) __attribute__((frr_format("frr_printf", a, b)))
349 #else /* !_FRR_ATTRIBUTE_PRINTFRR */
351 #define PRINTFRR(a, b) __attribute__((format(gnu_syslog, a, b)))
353 #define PRINTFRR(a, b) __attribute__((format(printf, a, b)))
356 /* frr-format plugin is C-only for now, so no point in doing these shenanigans
357 * for C++... (also they can break some C++ stuff...)
360 /* these should be typedefs, but might also be #define */
368 /* can't overwrite the typedef, but we can replace int64_t with _int64_t */
369 typedef unsigned long long _uint64_t
;
370 #define uint64_t _uint64_t
371 typedef signed long long _int64_t
;
372 #define int64_t _int64_t
374 /* if this breaks, 128-bit machines may have entered reality (or <long long>
375 * is something weird)
377 _Static_assert(sizeof(_uint64_t
) == 8 && sizeof(_int64_t
) == 8,
378 "nobody expects the spanish intquisition");
380 /* since we redefined int64_t, we also need to redefine PRI*64 */
388 #endif /* !__cplusplus */
389 #endif /* !_FRR_ATTRIBUTE_PRINTFRR */
395 #endif /* _FRR_COMPILER_H */